Check out this playlist of 11 tutorials on MainStage 3. MainStage is an incredible application for only $30 that allows you to do anything from add effects to live vocals, create keyboard presets for an entire set, and so much more. It's an incredible tool for musicians to use and these videos will help you get started and playing quick. Check them out!
Here is a great video of Ian Mcintosh, keyboardist for Jesus Culture, talking about using Ableton and Reason on the live stage.